Transmission unit provided with a swash plate (variants) and differential speed converter (variants) based thereon

ABSTRACT

A transmission and speed conversion device is provided with a wobble (presessional) plate. The transmission unit has two cases encompasing each other. The first case is embodied as a wobble plate in that it is capable of two independent motions: rotation and pressession around its own axis which is inclined with respect to the axis of the second case. The adjacent side surfaces of the two cases are embodied in the form of a shperical belt, the center of the sphere being disposed at the center of precession of the wobble plate. Race grooves are embodied on the adjacent case surfaces and communicate with each other via rotation bodies. The race grooves are inclined to each other where they contact the rotation bodies at an angle less than the self blocking angle of the wobble plate, allowing the device to operate in such a way that the rotation bodies are slip-free. The device can be provided with a system of angular races parallel with each other, and can operate as a friction-planetary transmission in which pressure is automatically regulated by load.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The invention relates to motion transmitting devices of the generalmechanical engineering, namely, to means for transfer of rotation withthe transformation of speed based on the mechanism with wobble(precession) plate, and may be used in drives of general use machinesand mechanisms.

2. Description of the Related Art

The converters of speed named and classified in according any aspects,but based on an identical principle of a tooth gearing with a wobbleplate are known.

Wave gear end-to-end transfer concerning to that is described in patentapplication of the Russian Federation N^(o) 940023896, MIIK F16H1/00.Transmitting unit of this gear contains a wobble plate with a face gearring which is in driving engagement with face plate of fixed cogwheel.The precession of the wobble plate is caused by wave actuator embodiedas the eccentric with a pressure roller. The wobble plate is connectedto output shaft by universal joint. In according to the same kinematicsare constructed a cone planetary precession gear (SU the USSR N^(o)1414976), wave gear with rigid parts (SU N^(o) 653458), cone wave gear(RU N^(o) 2145016). Similar kinematics, but with distinctions inembodiment of separate units are realized in speed transducers describedin patents of USA: U.S. Pat. Nos. 3,525,890; 3,640,154; 4,281,566;4,841,809; 5,562,560. Some of them have two transmitting units, i.e.realize two-stage gear. All speed transducers above described havecommon disadvantages resulting from tooth engagement. At first, this ishigh friction and high thermal losses especially under high speed ofrotation. Furthermore, only some few of teeth can be kept in drivingengagement in transmitting devises mentioned above thereby limitingtorque capacity.

Some of these disadvantages are eliminated in the speed transducers withnutation or precession system of torque transfer with cam drivingengagement of transmitting parts by means of rolling bodies (U.S. Pat.No. 4,715,249; U.S. Pat. No. 4,563,915; SU N^(o) 1427115). Thedifferential speed converter with a wobble plate (U.S. Pat. No.4,563,915) has transmitting unit composed of three members. The wobbleplate has a cam element associated therewith and having axially directedcam lobes. The patent further discloses that the lobes engage rollerswhich are constrained to move along the surface of an imaginary sphere;however, since the crests of the axially directed cam lobes are atslightly greater distance from center of the imaginary sphere than thevalleys, and since the rollers are at a fixed distance, the rollers willbe forced to disengage and reengage with the cam surface causing wear,noise and undesirable reciprocating forces. Said disadvantage iseliminated in devices described in patents U.S. Pat. No. 4,620,456 andU.S. Pat. No. 5,443,428. Transmitting unit in these devices alsoincludes three members, one of which is the wobble plate, and other twomembers are formed as solids of revolution. The wobble plate isintermediate part and provided at least with one cam surface formed asthe bent groove being in driving engagement by means of balls with a camat one of said solids of revolution. In the device of U.S. Pat. No.4,620,456 side surface of a wobble plate is bent by sphere, and thetrochoidal groove is located in a place of intersection of the lateraland the face surfaces, or at the face surface of a wobble plate. At anopposite end face of a wobble plate in one-stage converter the set ofslots being in engagement with the slots of solid of revolution by meansof balls is located. The solids of revolution are individually connectedto output shaft and to the housing of the converter accordingly. Forfixing angular position of balls from each other during runningsimultaneously over the edges or hollows of conjugated grooves there isa thin-walled separator between conjugated surfaces, in apertures of theseparator said balls are located. In a two-stage converter there areepitrochoidal grooves with different numbers of tooth at two oppositeend faces of a wobble plate, which grooves are conjugated withhypotrochoidal grooves located at the housing component and at theoutput component.

Precession of the plate occurs relative to the centre of precession,being the centre of symmetry of the system, and so the files of ballsmake nutation movement because of their centers are displaced from thecentre of precession. Balls make oscillatory movement, both in axial,and in a radial direction, that is during the operating of the mechanisma changing of an angle of displacement of engaged members occurs,resulting in vibration and in problems caused by it, namely noise anddeterioration for high-speed mechanisms. Furthermore, the grooves beingan epitrochoid and hypotrochoid are difficult in manufacturing.Understanding of it causes the authors to propose manufacturing of allcomponents of the transfer mechanism of plastic, thereby allowingproduction of grooves of the complex form by punching. It is obvious,that such transfers are not suitable for power mechanisms, and may beused only for apparatuses, watches etc. products.

In patent U.S. Pat. No. 5,443,428 there is described the converter ofthe same design but with even more difficult in calculation andmanufacturing cam periodic surface. The patent employs engaging elementswith undulating surfaces, but the surfaces are all designed to bespherically directed so that only angular displacement of the variouselements is encountered thus avoiding translational vibrations as wellas disengagement and reengagement problems. This transmission eliminatessliding contact thereby minimizing frictional losses, binding and othersources of inefficiency, wear and noise. However, each file of ballsmakes the complex movement superposed of precession relative to point ofintersection of plane of said file and axis of system and of planetarymotion relative to axis of converter. That is relative to this axisballs make radial movements thereby keeping an opportunity of noise andvibrations. Furthermore special requirements to the form of cam surfacesdo the converter hardly applicable in power drives of general use andmanufacturing.

There is known a speed converter (U.S. Pat. No. 1,748,907), transmittingunit of which consists of two members: male spherical head and femalewobble plate. On an internal spherical surface of a wobble plate alongan equatorial line hemispherical recesses are located in which the samenumber of balls are fixedly seated. These balls are in turn inengagement with a continuous curved groove formed in spherical head. Asthe wobble member nutates, the balls successively incite the head tomove rotationally by engaging the walls of the groove. In thistransmitting unit the center of precession of ball file is coincidentwith center of precession of the wobble plate, therefore the ball filewill be participate only in precession, thereby reducing exactingrequirements to the form of groove. The main disadvantage of theconverter is significant frictional losses caused by sliding contact ofballs with recesses in wobble plate

The decision of a problem developing transmitting unit in which rollerscontact with periodic grooves only by means of pure rolling, without asliding friction, is the object of the invention described inapplication WO008201043, chosen by us as a prototype of one variant oftransmitting unit. The motion transmitting unit comprises a male memberand a female member, both made in the form of solids of revolution withmeshing elements between them. In a simple construction the meshingelements may be n balls where n is a multiple of four, the balls meshingin a wavy groove having (n−1) or (n+1) waves in the male member, and theballs engaging also in n arcuate grooves in the female. The grooves ofmale and female members are made at part-spherical conjugated surfacesof the members. In this application transmitting unit is composed of twomembers arranged so that one embraces the other, one of which is a caseand the other is wobble element (swash plate). The differential speedtransducer on the basis of this transmitting unit comprises the firstshaft, second shaft and the frame. The swash plate is coupled to one ofsaid shafts by coupling means transforming swashing movement in rotary,and swash plate is coupled to other of members by second coupling meanstransmitting the rotation of the swash plate independently of itsswashing movement. Pure rolling motions of balls in grooves of male andfemale members are achieved in two ways. Firstly, in transmitting unitwith meridian slots, said slots are located at female member, therebycompensating different ways passable by a ball relative to inclinedfront of a wave in the circumferential groove and relative to meridianslot by means of a difference in the distance from contact points of aball with a male and female members up to the centre of sphere.

The second way is an altering the cross-section of the grooves in themale and female members thus causing the balls to rise and fall in thegrooves to alter the effective radial point of contact, thus alteringthe ratio and thus achieving equal constant instantaneous rollingvelocities of the balls on the surfaces of the male and female elements.Thus, in both ways the purpose is achieved by alignment of a way,passable a ball relative to both groove for same time. However, as haveshown our researches, it is not enough this condition to force balls tointeract with grooves only by rolling with the exception of sliding.

Furthermore, the prototype, as well as each of the above described speedconverters with a wobble element, has the fixed housing to which quiteconcrete detail is connected in each concrete design, and transmittingunit has the internal volume limited to the housing. The converter withthe own housing, as a rule, is not built in drive mechanism and soplaced and packed outside, thereby increasing dimensions of the deviceas a whole. Thus, an object of the invention is the creation ofuniversal transmitting unit which is simple in manufacturing, minimal inspecific weight and sizes characteristics and convenient for building inthe machines and mechanisms, and also the creation of a speed converterbased on it.

The condition of pure rolling of balls discovered by us appearedsuitable not only in transmitting units with periodic grooves. Itsapplication in ball friction-planetary transmitting units has allowedcreating the whole class of the elementary transmitting mechanisms whichare devoid the main disadvantage of all friction gears, namely,occurrence slippage with wear process of details. Transmitting unit ofknown ball friction-planetary gears (SU N^(o) 844863, SU N^(o) 1229484,and RU N^(o) 2010141) comprises two solids of revolution with grooves,and separator placed between the spherical surfaces of said solids ofrevolution. In sockets of separator some rolling elements being ballsare located. One of solids of revolution is connected to input shaft,another is connected to the frame or to other shaft, and the separatorwhich transforms orbital movement of balls to rotation of an outputshaft is connected to the shaft. With simplicity of a design, the basicproblem of friction-planetary ball gears is necessity of the pressuremechanism which prevents slippage of balls under increasing of thetorque or as a result of deterioration of balls and grooves while inservice. Press mechanisms, basically, use various elastic elements.

The technical result of the present invention is elimination of slidingor skidding motion between the balls and the walls of the grooves intransmitting unit with a swash plate. Thus for friction-planetary ballgears the problem of automatic control of pressing a ball withoutapplication of special mechanisms is solved.

The transmitting units according to this invention are a basis not onlyfor differential speed converters, but they also may have independentapplication for example in mixers. According to this invention it ispossible to develop the mechanism for direct transformation ofoscillatory energy (for example, energy of sea waves) to energy ofrotation with the increased or reduced speed of rotation. The additionaltechnical result achievable by individual variants of the invention isthe design in the form of bearing unit free of the stationary housing;instead any member becomes fixed one when setting this unit to itsworkplace.

It is simpler to understand the substance of the invention withconsideration an example of transmitting unit with a wobble plate infriction-planetary ball gear; therefore we shall start the descriptionby this embodiment of the invention.

SUMMARY OF THE INVENTION

According to the invention, torque transmitting unit comprises twomembers in the form of solids of revolution. One said solid ofrevolution is arranged to make two independent movements: wobblingrelative to another and rotation around of the own axis inclined withrespect to axis of other solid of revolution and so may be designated asa wobble (precessional) plate. On the adjacent surfaces of said case andwobble plate endless grooves are made interacting with each other bymeans of rolling bodies being in continuous contact with grooves of bothmembers. The tilting angle of the wobble plate is chosen so that thegrooves in a place of contact with rolling body are inclined to eachother by angle less or equal to the self-blocking angle of rolling body.In practice this angle for usual constructive materials may be acceptedin a range of 0,1-10 degrees. If the above condition is catered for, therolling bodies, for example being balls, are pressed between surfaces ofa wobble plate and the second member, therefore rotation one said memberforces balls in orbital movement relative to another member withoutslippage. Orbiting balls just as cams push wobble plate causing it toprecess. Thus, transmitting unit with a wobble plate realizes aprinciple of friction-planetary ball gear in which planetary movement ofa ball is transformed to precession of said wobble plate and vice versa.

With this configuration, said angle of grooves inclination to each otherprovides automatic adjustment of pressing a ball between them, sinceunder increasing of load or deterioration of a ball and grooves, theball is displaced along of azimuth in area of smaller distance betweengrooves.

For range extension of gear ratio, the cross sections of grooves have tobe in such form that zones of contact of rolling body with the walls ofgrooves lay at different distances from rotation axis of a rolling body.

Transmitting unit with a wobble plate according to the invention may beembodied in two constructive modifications: disk-shaped and coaxial. Inthe first modification the solids of revolution are formed as disks, oneof which wobbles relative to another. The annular endless grooves arearranged at the flat surfaces of disks faced to each other and are incontact with rolling body located between this grooves. To meet acondition of groove inclination to each other by angle less than angleof self-blocking, the tilt angle of a wobble plate with respect to axisof transmitting unit should be within the limits of 0,2-15 degrees. Thenthe rolling body itself is established in that place of a circle ofgrooves where the distance between the grooves meets to the size of therolling body.

If the rolling body is a ball, the side walls of a groove at any ofdisks preferably to be resilient flexing to each other. Thus the radiusof curvature of a groove cross section becomes variable; the point ofthe ball contact with a groove will be displaced from an axis of a ballrotation under load variation. Thus, the transmitting unit is capable tovary gear ratio depending on loading automatically.

In the coaxial modification of the transmitting unit the solids ofrevolution are embodied so that one will embrace the other, one of themis wobble plate and the other is a case, both having side surfaces facedto each other in the form of spherical zones with the centre of spherebeing in the centre of precession of a wobble plate. Generally, eachgroove in a wobble plate and in a case is realized as a set of closedannular grooves parallel with respect to each other, lying in planesperpendicular to axis of rotation of the appropriate member. The rollingbodies are the balls located in points of intersections of the wobbleplate grooves with the case grooves.

In particular cases, in the wobble plate the set of grooves constitutessingle groove lying in an equatorial line of the wobble plate andintersecting with one or several grooves in the case. Single groove inthe case is displaced from equatorial circle of sphere by the distanceequal to half of oscillation amplitude of the wobble plate and isengaged with a groove of the wobble plate by means of single ball.

To balance the set of balls relative to the case axis, two annulargrooves are located at the different sides of the large circle of sphereby distances equal to half of oscillation amplitude of the wobble plate.Annular grooves in the case are engaged with a groove in the wobbleplate by means of two diametrically located balls. The same balancedsystem of balls is achieved if the case have single groove in the lineof large circle of sphere with the balls located at two diametricallyopposite points of intersection this groove with a groove in the wobbleplate.

Integration of two above described variants in one design is possible.Then three grooves are located in the case, one being in the line of thelarge circle of sphere and two being on both sides of this larger circleat distances equal to half of oscillation amplitude of the wobble plate.In engagement with this grooves are four balls located in pairsdiametrical opposite points in mutually perpendicular diameters.

Also, it is possible the combination of one groove in an equatorialplane of the case with two grooves in the wobble plate spaced apart ofan equatorial line by the distances equal to half of oscillationamplitude of the wobble plate.

The grooves in the case may be located at separate and independentlyrotating annular case parts. It will be noted that in all abovedescribed constructions, there is necessarily to meet the conditionproducing to the angle of a grooves inclination to each other. Unlessthe above condition is catered for, a slippage of balls occurs therebyupsetting their frictional communication with grooves and failing torquetransfer.

The second variant of the invention is realized in transmitting unitwith a wobble plate provided with circumferential wavy grooves. Forachievement of the technical result mentioned above, this transmittingunit, as well as the prototype, contains a case and a wobble plateembodied so that one will embrace the other. Their side conjugatedsurfaces are in the form of spherical zones with the centre of spherelying in the centre of the wobble plate precession. Periodic in azimuthdirection grooves are made in equatorial area of the conjugated surfacesof the case and the wobble plate faced to each other. At least one ofsaid grooves is formed as endless and wavy bent in an axial directionone. The grooves are engaged with each other by means of the ballslocated in intersections of grooves. In contrast to the prototype,grooves in a place of contact with balls are inclined to each other byangle less to an angle of self-blocking of balls. This condition is met,if angle α of a periodic groove front inclination to equator of thewobble plate and the appropriate angle β at the case are in thefollowing ratios to the wobble plate tilt angle γ:α−β−Γ≦?10, at α≧?;   (1)β−δ+γ≦?10, at α<β;  (2)

Angles α and β both depend on number of the periods and on amplitude ofappropriate grooves. Amplitudes, in turn, are connected to the tiltangle of a wobble plate. In any case, by way of varying these values itis possible to achieve performance of conditions (1) and (2).

In comparison with the prototype, in our invention the condition of achoice of the groove period numbers is changed also. The number of ballsn may be anyone. However, with a small amount of balls (within thelimits of 10-20) for achieving of the counterbalanced system of balls itis desirable that the number of balls is even. Number of the periods ofgrooves N1 and N2 in the wobble plate and in the case accordingly are inthe following ratios to number of balls n: N1=kn±1; N2=qn±1, where k andq are integers or numbers of a kind 1/m where m is the number by which anumber of balls is divided without the rest. Expansion of a range ofpossible numbers N1 and N2 not only provides expansion of a gear ratiorange for one transmitting unit with the certain number of balls, butalso increases number of combinations of the groove periods at which thecondition of self-blocking of balls is satisfied. It will be noted, thatthe friction-planetary transmitting unit of a coaxial configurationdescribed above is, as a matter of fact, the particular case with thegroove period numbers N1=0 and N2=1.

Periodic grooves on both members may be closed wavy bent. The groove inone of members can be made interrupted in the form of system of slotsspaced over the circle and extended along of meridians of sphere.

In the next embodiment for increasing of unit functionalities, the caseis slit along an average line of the bent groove thereby forming twoindependently rotating parts of the case. The groove on each of partsrepresents system of the half waves with different number of theperiods.

The differential speed converter on the basis of the above describedtransmitting units comprises three shafts. The wobble plate oftransmitting unit is connected to one of shafts by means of mechanismfor independent transformation of its precession motion into rotation ofa shaft and on the contrary. Moreover, the wobble plate is connected tosecond of shafts by means of the mechanism transferring its rotationabout an inclined axis irrespective of its wobbling. The second solid ofrevolution is directly connected to the third shaft.

For ball friction-planetary transmitting units of disk configurationsthe mechanism for transformation of a wobble plate precession intorotation of a shaft and on the contrary is embodied as the face camcooperating with a wobble disk through the bearing, and the second shaftis the frame of the transmitting unit and is connected to a wobble plateby means of the device preventing rotation of the last.

For coaxial transmitting units it is expedient to make all shaftscoaxial and hollow whereby forming a coaxial design composed of caseslike bearing unit.

The converter with transmitting unit, in which the case consists ofindependently rotating parts, is supplied with additional shafts whichare directly connected to the said parts.

As the mechanism for independent transformation of precession of awobble plate into rotary movement of the first shaft and on the contrarymay serve skew crank shaft on which the wobble plate is set by bearing.Also, as the mechanism for transformation of precession in rotarymovement may serve any friction-planetary ball transmitting unit ofcoaxial design realized on the same wobble plate at its side opposite tothe basic transmitting unit. Then the case of the friction-planetaryunit serves as the first shaft of the converter.

The mechanism of independent transferring a wobble plate rotation to thesecond shaft may be embodied as gimbals joint, as a system of flexiblerods and hinges, or as a bevel gear.

Transmitting units of coaxial design allow creating two-stage speedconverters without significant increase of dimensions. The stages oftransmitting units are located in series along the same axis or arearranged that one embraces the other (coaxial design of two-stage speedconverter). The two-stage converter of coaxial design, in turn, may bemade by two variants. In the first variant of coaxial design thetransmitting units of both stages use the same wobble plate. For thispurpose, at the wobble plate of the first stage transmitting unit atside opposite to this unit, the transmitting unit of the second stage isarranged, i.e. the whole system is formed of three elements in seriesembracing one another: case, wobble plate, case. The second stagetransmitting unit in this variant serves as the mechanism transferringthe rotation of the wobble plate to the converter shaft connecteddirectly to the case of the second stage transmitting unit. As themechanism transferring wobble plate precession into rotation and on thecontrary no all above described means may be used because of some ofthem use the second side of a wobble plate which side in this variant isoccupied with the second transmitting unit. For this variant the specialmechanism is developed representing two hollow shafts, entered by meansof bearings between internal and external cases at opposite end faces.Each of shafts is made with an identical skew crank. The wobble plate isset on both crank shafts by means of bearings. The hollow shafts may bemade with the face cams cooperating with wobble plate end faces throughthrust bearing.

In a second variant, the two-stage converter is consisted of twoseparate transmitting units embracing each other. Wobble plates of bothunits are faced to each other. The mechanism transferring the precessionof each of wobble plates into rotation represents a hollow shaft enteredbetween wobble plates of both stage and having on both side surfacesfaced to wobble plates the elements causing a precession of the wobbleplates.

Elements causing a precession of wobble plates may be designed in formof skew cranks with an identical or opposite inclination. The wobbleplates are set on said cranks by means of bearings. With an identicalinclination of cranks the wobble plates oscillate synchronously, withopposite inclination of cranks they oscillate in the opposite phases.Elements causing a precession of wobble plates also may be made byanother way. In each pair consisting of hollow shaft and wobble plate,annular groove and annular ledge interfaced with each other by means oftwo opposite balls are made on the lateral surfaces of said hollow shaftand wobble plate faced to each other. Balls are located between groovewalls and a ledge at the opposite sides of the ledge. The wobble platesof both stages are connected with each other by means of unittransferring rotation, so that the transmitting unit of the second stagecarries out the function of the mechanism transmitting the wobble platerotation to a shaft directly connected to the case of second stagetransmitting unit.

The two-stage speed converter may comprise two coaxial transmittingunits located one after another along one axis. In this variant thewobble plates of both stages are connected by means of mechanismtransferring rotation between parallel shafts. A mechanism transferringprecession into rotation of a shaft is made the same as that for theone-stage converter and should provide synchronous precession of wobbleplates. In the result, wobble plates during precession are parallel eachother. This converter being similar externally to the two-stageconverter described in the description to patent U.S. Pat. No.5,443,428, nevertheless essentially differs from it in that the periodicgrooves on both wobble plates are located in equatorial area. That is,the files of balls in both stages participate in precession about thepoint lying in a plane of a file of balls, and the nutational submotionis absent in the movement of balls. At that there is essentialsimplification of requirements to the form and working accuracy ofgrooves for full elimination of noise and vibrations.

The unit transferring the rotation between parallel shafts may berealized on base of any known circuits. For these purposes the mechanismwith parallel cranks suits well. The most preferable from the point ofview of reduction of losses by friction is the mechanism with parallelcranks with ball engagement, as, for example, presented in patents U.S.Pat. No. 4,829,851 or U.S. Pat. No. 4,643,047. Said unit may be realizedalso as a shaft to which each of wobble plates is connected by means ofgimbals joint. For this speed converter the original mechanism fortransformation of precession motion of wobble plates to rotary movementand on the contrary is developed. It includes a case located on an axisbetween stages of the converter; said case is supplied with an externalannular ledge. The case is made with two parallel skew cranks on whichthe wobble plates are set by means of bearings. The annular ledgeproject from limits of external cases of both transmitting units, andits external profile is made in form of an element of worm, conic or afriction gear. Such mechanism transfers precession motion of plates toshaft, the axis of which is perpendicular to the general axis oftransmitting units. That is, the speed converter is intended forrotation transferring between two skew shafts.

The two-stage speed converter with a sequential arrangement of stagesmay be made with the precession of plates in opposite phases. In thisvariant, wobble plates of both stages are connected by means of themechanism transferring rotation between inclined shafts, and themechanism transferring precession movement provides precession of platesin opposite phases. It is necessary to note, that the speed convertersformed under the invention are effective only with small angle γ ofinclination of a wobble plate. Otherwise, transferring of rotationbetween the details inclined to each other under the wide angle willneed the mechanism which considerably decreases effect of absenceslippage of balls in the most transmitting unit. At the same time, forsome variants of transmitting unit the angle γ may appear wide enough tomeet ratios (1) and (2). Transmitting unit with both cases being wobblesplates allows bypassing this contradiction. In this variant, the angle γin the ratios (1) and (2) to be understanding as an angle of aninclination of wobble plates with respect to each other. At the sametime, each of wobble plates has an inclination to an axis oftransmitting unit twice less. Also this angle in the mechanismtransferring the rotation accordingly decreases.

Such transmitting unit may be of a basis of set of various designs ofdifferential speed converters with various functionalities. Generally,the differential speed converter contains at least three coaxial hollowshafts, forming a coaxial design composed of cases likewise bearingunit, and transmitting unit with two wobble plates. Wobble plates areconnected to one of shafts by means of mechanism of independenttransformation precession motion into rotary and on the contrary, andthey are connected with other two shafts by units transferring rotationbetween inclined shafts.

It is possible to excite a precession of wobble plates in a mode ofopposite phases. In this variant, the speed converter operates similarlyto that with single wobble plate, but the angle of an inclinationbetween the wobble plates determining angular characteristics of grooveswill be equal to the sum of angles of precession of each plate. Suchembodiment allows reducing an angle of precession of each wobble platewhile keeping an angle of an inclination of plates to each other. Itsimplifies requirements to mechanisms transformation of precessionmotion of the plates to rotation of a shaft and improves conditions oftheir operation. At the same time, reduction of an angle of precession,i.e. an angle of an inclination of each plate to an axis of theconverter, simplifies requirements to mechanism transferring rotationbetween inclined shafts, and allows transferring higher torque withother things being equal.

The mechanism of transformation of precession movement of wobble platesin this variant may be made in form of two coaxial hollow shaftsconnected with each other, one of which is located outside of anexternal wobble plate, and the other is located inside an internalwobble plate. In each pair composed of a hollow shaft and wobble plate agroove and annular ledge are made on their side surfaces faced to eachother. Said groove and annular ledge are interacting by means of twoballs oppositely located between walls of a groove and a ledge atopposite sides of the ledge. Balls in each pair are located so thatwobble plates have opposite inclinations.

The same result can be achieved, if the surfaces of hollow shafts facedto wobble plates and connected with each other are provided with skewedcranks with an opposite inclinations and cooperating with wobble platesby means of bearings.

For expansion of functionalities of the converter, it is desirable themechanism transferring precession motion of plates to rotation of ashaft to form as two separate elements independent from each other, eachof which is connected to separate shaft of the converter. This converterhas an additional input shaft. With an equality of phases and speeds ofprecession of the wobble plates (i.e. two input speeds), we have a zerospeed at an output of the mechanism. With an opposite direction of inputspeeds, or with an opposite precession phases, the mechanism operates asthe speed converter with two inputs and two outputs with a differentratios of their speeds.

BRIEF DESCRIPTION OF DRAWINGS

The invention is illustrated by graphic materials in which arepresented:

FIG. 1 is the schematic representation of the ball friction-planetarytransmitting unit in disk embodiment;

FIG. 2 is a diagram illustrating interacting of grooves and balls inthis unit by scanning;

FIGS. 3, 4, 5 and 6 show various embodiments of a groove structure forexpansion of transfer ratio range;

FIG. 7 is a sectional view showing the speed converter with thistransmitting unit;

FIGS. 8-19 illustrate various constructive variants of ballfriction-planetary transmitting unit in coaxial version, at that FIGS.8, 10, 12, 14, 16, 18 show the general view of variants of transmittingunit, and at FIGS. 9, 11, 13, 15, 17 and 19 are shown diagrams ofinteraction of their grooves and balls;

FIG. 20 illustrates the axial section of transmitting unit with periodicgrooves;

FIG. 21 is a diagram, illustrating relation of tilt angle of a wobbleplate, angles of an inclination of periodic groove wave fronts and anangle between the grooves in a place of contact to a ball;

FIGS. 22-27 are representation an explanatory diagrams of interacting ofgrooves and balls for different variants of transmitting unit. Diagramsat FIGS. 22 and 23 illustrate an opportunity of satisfying the angularcondition by means of a choice groove period numbers while keeping anangle of an inclination of a wobble plate and amplitudes of grooves.Diagrams on FIGS. 24 and 25 illustrate the possibility of satisfying theangular condition by changing amplitude of grooves while keeping anumber of the periods. And, at last, at diagrams 26 and 27 there isshown the way to achieve of satisfying the angular condition by changingan angle of an inclination of a wobble plate;

FIGS. 28 and 29 show the axial section and the diagram of interaction ofgrooves and balls, accordingly, for transmitting unit in which one ofperiodic grooves is made interrupted and composed of meridian slotsspaced apart over the a circle;

FIGS. 30 and 31 represent the axial section and the diagram ofinteraction transmitting unit members with a case composed of twoseparate parts;

FIGS. 32, 33, 34, 35 represent the sectional view of differential speedconverters with the coaxial transmitting unit differing by designs ofmechanisms transferring precession motion of a plate into rotation of ashaft, and also, by units transferring rotation of a wobble plateirrespective of its wobbling (i.e. by units of transfer of rotationbetween inclined shafts);

FIGS. 36 and 37 represent the two-stage converter with transmittingunits of each stage realized at single wobble plate. Converters differfrom each other only by designs of the mechanisms transferringprecession motion of a plate into rotation of a shaft;

FIGS. 38 and 39 represent two-stage converters consisting of twotransmitting units embracing one another and differing from each otherby the design of mechanism transferring precession motion into rotationof a shaft;

FIGS. 40, 41, 42, 43 are diagrams illustrating different embodiments ofthe two-stage converters with arrangement of stages in series.

FIG. 44 schematically illustrates transmitting unit with two wobbleplates;

FIGS. 45, 46, 47 illustrate some embodiments of converters on the basisof transmitting unit of FIG. 44.

It will be noted that all versions of designs of the converter accordingto the invention are not limited to the mentioned figures.

BEST MODE FOR CARRYING OUT THE INVENTION

Transmitting unit in FIG. 1 contains two solids of revolution 1 and 2 inform of disks; circumferential closed grooves 3 and 4 are cut upon facedto each other surfaces of the discs. The disk 2 is capable to precess.For this purpose, its axis of rotation OO₁ is inclined to general axisCC₁ of transmitting unit, and the disk 2 rotates around of an own axisof rotation OO₁ and also wobbles relative to axis CC₁ irrespective ofits rotation, i.e. the disk 2 is a wobble (precessional) plate. Incontact with grooves 3 and 4 there is a rolling body 5; in this case itis a ball. FIG. 2 represents the diagram of interaction of a ball 5 withboth grooves 3 and 4. The lines 6 and 7 represent the lines of movementof the centre of a ball 5 relative to disks 1 and 2 accordingly. Thetilting angle γ of wobble plate 2 with respect to the disk 1 must to besuch that the angle φ between grooves 3 and 4 in a place of theircontact with a ball 5 did not exceed the angle of self-blocking of theball. Self-blocking of rolling bodies is well known and is used in,so-called, free-wheel clutch (see, for example, Polyakov V. C., BarabashI. D. “Couplers”, L. “Mashinostroenie”, 1973, p.225). The angle ofself-blocking is understood as the angle between two surfaces on whichthe rolling body is rolled up in a narrow part of a wedge due tofrictional forces and is clamped between these surfaces. The angle ofself-blocking of rolling bodies depends on factors of friction of arolling body relative to grooves, which, in turn, depend on a materialand on final polishing of rolling bodies and grooves surfaces.

As have showed our researches, it is expediently to choose the angle φwithin a range of (0,1-10) degrees. However, sometimes, for example, forrolling bodies made of an elastic material or for grooves with africtional covering, this angle may to lie within a range of 15-17degrees. During a rotation of one of disks (for an example, a disk 1)relative to another disk, the ball 5 will roll up into a narrow part ofa wedge between grooves 3 and 4. In contrast to free-wheel clutch,blocking of a ball in our transmitting unit will not take place, as awobble plate 2 and a ball 5 both have two degrees of freedom. Underaction of pressure of the ball 5 against the groove 4, the plate 2 willbegin to wobble. The speed of planetary motion of the ball centre istwice smaller than speed of the point at the ball surface in a place itscontact to the groove 3. Planetary movement of a ball will causeprecession of a plate which angular speed is twice smaller than inputspeed of rotation, i.e. the transmission ratio of the unit is 2:1.Inclined position of a wobble plate 2 results in that the ball 5 isconstantly pressed to a surface of grooves 3 and 4 without additionalclamping mechanisms which are necessary in usual ball friction-planetarytransmitting units. With increasing of load, or with deterioration ofgrooves, a ball 5 runs in narrower part of a wedge between grooves 3 and4, thereby automatically increasing the pressing effort. Thus,transmitting unit operates without slippage of a ball since speed ofplanetary moving of the ball 5 is coordinated with speed of its rotationabout an own axis. The tilting angle of a wobble plate is functionallyrelated to an angle φ between grooves by a following equation:tg γ=π/2tg φ,i.e., when the angle φ is in the range of 0,1-10 degrees, the tiltingangle of a wobble plate should be chosen in the range of 0,2-15 degrees.

As well as in usual ball friction-planetary unit, it is possible toincrease a range of transmitting ratio in above unit by changingeffective rolling radiuses R1 and R2 of rolling bodies 5 in grooves 3and 4 (see FIGS. 3, 4 and 5). For this purpose structures of crosssection of grooves 3 and 4 are formed such that rolling radiuses of ballR1 and R2 in grooves 3 and 4 would be not identical. The transmissionratio i₁₂ from a disk 1 to a disk 2 is: i₁₂=1+R1/R2. FIGS. 5 illustratesthe variant when the difference arises in result of applying of arolling body in the form of the stepped roller contacting to grooves 3and 4 by steps 6 and 7 having different diameters. FIG. 6 shows, how tomake transmitting unit with automatic adjustment of torque value. Theexternal annular part of any disk (in this case a disk 1) is embodiedwith a groove formed with resilient flexing walls 8. In other words, thecross section of groove may change a radius of curvature. At FIG. 6 theresilient flexing mobility of walls 8 is provided by means of twoannular pinches 9. When increasing of the load at input shaft the ball 5moves over circle in narrower part of a wedge between grooves thusunclenching walls 8 of groove 3 from each other. A point of the ballcontact with the groove 3 moves from point B to point C therebyincreasing effective rolling radius R1 of the ball 5 in the groove 3.This increase will cause increase of the transmission ratio and thetorque.

The differential speed converter with disk friction-planetary unit (seeFIG. 7) contains a shaft 10 rigidly connected to a solid of revolution1, and the shaft 11 connected to a wobble plate 2 by means of mechanismtransferring its precession into the rotation of a shaft 11. Themechanism in this example represents the face cam 12 cooperating with awobble plate 2 through bearing 13. The housing formed by two flanges 14and 15 serves as the third part of the converter. The wobble plate 2 isconnected to the flange 14 by means of unit preventing its rotationwhile permitting its wobbling. This unit is made in the form of rods 16passing through apertures in a peripheral annular part 17 of wobbleplate 2. Rods 16 pull together flanges 14 and 15 among themselves.Apertures for rods 16 in a wobble plate have the sizes admittingmisalignments during wobbling of the plate. Shafts 10 and 11 are set inthe housing flanges 14 and 15 by means of bearings 18 and 19.

Transmitting friction-planetary unit of coaxial embodiment contains acase 20 and a wobble plate 21 embracing one another. FIGS. 8, 10 and 12show transmitting units in which the wobble plate 21 surrounds a case20. It is necessary to note, that the inverted configuration of unitswhen the wobble plate 21 is surrounded by a case 20 are quite efficient.Conjugated side surfaces 22 and 23 of the case 20 and of the plate 21are the parts of sphere with the centre of sphere (point C) located inthe centre of symmetry of both said details. The wobble plate 21 isarranged to have an opportunity of precession about a point C. Inconjugated side surfaces 22 and 23 the grooves 24 and 25 are made. Thegroove 25 in the wobble plate 21 represents the annular flute cut in theline of equator of a wobble plate spherical surface.

The groove 24 is the annular groove shifted from an equatorial line of aspherical surface 22 for distance equal to half of oscillating amplitudeof the plate 21. Both grooves in cross section have the form of asemicircle and in their intersection point the ball 26 is continuouslycontacting to both annular grooves. 27 and 28 are the sites of averagelines of grooves 24 and 25 in lateral development.

In other embodiment of this transmitting unit (FIG. 10) on a surface ofa case 20 two symmetric parallel annular grooves 24 and 29 are madelocated at both sides from equator by distances from it equal to half ofoscillating amplitude of the plate 21. At the intersections of grooves24 and 29 with a groove 25 two balls 26 and 30 are located. At thediagram of FIG. 11 number 31 designates a centerline of a groove 29.

At FIG. 12 the groove 32 is located in the case 20 in line of itsequator and engages a groove 25 in a wobble plate by means of twoopposite balls 33 located in places of intersections of grooves 32 and25. At FIG. 13 said places of intersections are the points ofintersections of centerlines 28 and 34 of grooves 25 and 32.

Unit presented at FIG. 14 combines (into one) two previous embodiments.There are made three annular grooves 24, 29 and 32 parallel each otherin surface of the case 20. Balls 26, 30 and two balls 33 are located inthe grooves in places of their intersections with the groove 25 in awobble plate. Here it is necessary to note, that the number of grooveson a surface of a case may be more than three, the main thing that theyare parallel with respect to each other and lay in planes perpendicularto axis of rotation of the case 20, and balls should be located inplaces of intersections of these grooves with a groove 25 in the wobbleplate. At the same time balls 33 which are engaged with a groove 32 inline of the equatorial circle of sphere are located in a circle ofannular grooves in the antipodes. I.e. the system of balls iscounterbalanced. The balls in other grooves are not counterbalanced;therefore for each groove located at one side of equator on this case itis expedient to make a symmetric groove at other side of equator.

FIG. 16 shows the variant of unit in which there are two ring grooves 35and 36 in a wobble plate, said grooves are located on the differentsides from an equatorial line of a wobble plate by distance from itequal to half of the oscillating amplitude of the plate. The groove 32in the case is cut in line of the equatorial circle of a sphericalsurface and is engaged with grooves 35 and 36 by two balls 26 and 30located in places of intersections of centerlines 37 and 38 of grooves35 and 36 with a centerline 34 of groove 32.

Basically, the variant with system of a few grooves in a wobble plateand system of few grooves in a case is possible. It increases a numberof the balls cooperating with members the unit. The increase of theballs number distributes power streams among more number of cooperatingelements and increases the maximum torque transmitted by means this unitwith other things being equal.

The case 20 may be composed of separate rings 39, 40, 41, in each ofwhich there is cut one groove (see FIGS. 18 and 19). Rings may rotatearound of the common axis independently from each other. Suchtransmitting unit has the increase number of input and output elementsthereby expanding its functionalities. Characteristic operate propertiesof converters with such transmitting units will be considered below.

Transmitting unit with a wobble plate with periodic grooves representstwo cases 42 and 43 where one case embraces the other. The case 43 isfree to rotate around of axis BB₁ inclined to axis OO₁ of transmittingunit, and also to precess relative to a point C being the point ofintersection of said axes. That is, the case 43 is a wobble plate. Thefaced to each other side surfaces of the case 42 and of the wobble plate43 are parts a sphere of radius R with the centre of sphere in a pointC. In equatorial areas of said surfaces periodic in azimuth directiongrooves 44 and 45 are cut engaged each other by means of a file of balls46. One or both grooves are made in the form of the closed flutes ofsemicircular cross section and are periodically bent in an axialdirection. The tilting angle γ of the wobble plate 43 and also the formof periodic grooves 44 and 45 are chosen such that angles of aninclination of grooves with respect to each other in a place of theircontact with rolling bodies 46 did not exceed the angle of self-blockingof rolling bodies. FIG. 21 is schematic representation of fronts 47 and48 of grooves 44 and 45. During the one full wobbling of the plate 43the file of balls 46 precess together with the wobble plate. At that,each ball interacts with the flange 48 of wave groove 45 and moves overcircle relative to the case 42 by an angle corresponding to the periodof the groove 45. At the same time balls 46 like cams press againstfront 47 of a wave groove 44 in the case 42 and cause its turningrelative to a file of balls 46 by an angle corresponding to the periodof a groove 44.

The total turn one case relative to another case for the full cycle ofwobbling movement of the plate will occur by an angle equal to the sumor to the difference of these turns, depending on what front of grooveballs will act. Thus, the transfer ratio i of the unit is determined byexpression:1/i=1/N ₁±1/N ₂   (3),where N₁ and N₂ are the numbers of the periods of grooves 44 and 45accordingly. Accomplishment of the angular condition results in being ofeach ball in wedge-shaped crack between two inclined surfaces S1 and S2with the angle between them which is less than the angle ofself-blocking of balls. During moving one of this surfaces, for exampleS2 relative to S1, (that corresponds to wobbling of the plate 43) balls46 roll up in a narrow part of a wedge between surfaces S1 and S2without slipping, and press against the front 47 of the wave groove 44,forcing it to turn, as it was described above. At the same time,frictional forces arising in result of rolling blocked ball and itinteracting with one of surfaces cause said surface to turn relative tothe file of balls. As far as the file of balls 46 and the wobble plate43 both have two degrees of freedom, then running of balls and themoving of cases under action of frictional forces and pressure arecoordinated with each other, i.e. balls will roll in wave grooves 44 and45 without sliding.

In the patent application WO008201043, as a condition of pure ballrolling is accepted equating of a rolling distances passed by a ballrelative to a groove 45 in the wobble plate 43 and relative to a groove44 in the case 42. However, this condition is not sufficient. If theangle between grooves in a place of contact with balls is greater thanthe angle of self-blocking of balls (as it is represented on drawingsand diagrams in disclosure of application WO008201043), then the ballwill slip out of a wedge and will be kept in a place of intersection ofgrooves only by their opposite walls 49 and 50, i.e. the ball will beonly a cam. At FIG. 21 the whereabouts of a ball in this variant isshown by means of shading. It is obvious, that in this case, a ball willbe necessary to sleep relative to any of surfaces (47, 48, 49 or 50),and availability of greater area than the size of balls will cause theirbeating and the increased deterioration.

The tilting angle φ of grooves to each other depends on tilting angles δand β of fronts 47 and 48 of grooves 44 and 45 to equatorial lines ofthe case 42 and the wobble plate 43 accordingly, and also the angle φdepends on tilting angle γ of a wobble plate, and is determined as:Φ=α−β−γ, if α≧?  (4) orφ=β−α+γ, if α<β  (5)

As it was shown above, for usual constructional materials the angle ofself-blocking lays within the limits of (0,1-10)°, therefore thecondition φ<10° (6) should be satisfied. In general, angles α and βdepend on amplitudes of a bend and on number of the periods of grooves.Numbers of periods N₁ and N₂ of grooves in the case 42 and in the wobbleplate 43 accordingly are depend on each other because the integer of theperiods should be stacked on the same circle of the radius R. In thedescription of application WO008201043 it is specified, that numbers ofthe periods of grooves should differ from number of balls by unit, andfrom each other by two, thus the number of balls should be multiple offour. Our researches have shown, that number of the groove periods N₁and N₂ and number of balls n are connected by ratio: N1=kn±1; N2=qn±1,(7) where k and q are integers, or they are numbers of a kind 1/m wherem is the number by which the number of balls is divided without therest. The number of balls as already it was told earlier may be anyone.

Thus, in our version, from all variety of combinations of numbers N₁ andN₂ satisfying to condition (7), it is necessary to choose such at whichthe inequality (6) is satisfied. FIGS. 22 and 23 illustrate anopportunity to achieve reduction of an angle φ by means of changing N₁and N₂. Numerals 51 and 52 designate average lines of grooves 44 and 45in the case 42 and in the wobble plate 43 accordingly. 53 is a line onwhich a point of a wobble plate surface moves during precession. Numeral54 shows a motion path of balls 46. Amplitude of grooves and tiltingangle of a wobble plate 43 are identical in both figures. In the firstversion, when N₁=3, N₂=13 and n=4 angles between grooves exceed anglesof self-blocking, at least, in two positions of balls 46. At FIG. 23average lines of grooves 51 and 52 are intersecting by angles less thanthe angle of self-blocking at all positions of balls 46. Period numbersof grooves and a number of balls are accordingly three, nine and four.

It is possible also to adjust an angle φ by changing of grooveamplitudes, or by changing tilting angle of a wobble plate while keepinggroove period numbers. These situations are illustrated at FIGS. 24, 25,26 and 27. At FIGS. 24 and 25 there are shown the average lines 51 and52 of grooves having the numbers of the periods fifteen and nine, andnumber of balls is eight. Minimal angle of grooves intersection at firstof this figures exceeds 10 degrees, i.e. it is more than the angle ofself-blocking. At FIG. 25, with decreasing of amplitude A1 of a bentgroove in the case 42, maximal angle of groove intersection does notexceed the angle of self-blocking. In this version, all balls 46 willoperate in a mode of self-blocking, i.e. without slippage.

FIGS. 26 and 27 differ of each other only by the tilting angle φ of thewobble plate 43. It is obvious, that in transmitting unit at FIG. 27 thecondition (4) is satisfied, and balls will move without slippage.

The groove in one of cases may be made interrupted. At FIG. 28 theperiodic groove in the case 42 is formed as the system of the slots 55spaced apart along of circles in a spherical surface. Each slot islocated in meridian line of sphere. At FIG. 29 as well as on theprevious figures, numerals 51 and 52 designate average lines of theappropriate grooves. It is obvious, that such transmitting unit willoperate without slippage of balls 46 with very abrupt front of a bentgroove 45 while with small tilting angles of a wobble plate 43, sincethe appropriate condition in this variant is transformed to expressionφ=90°−α+Γ<10°. At that, the condition of pure rolling will be satisfiednot for all balls 46. For the balls located in points E and F thecondition of self-blocking is impracticable at any values of α, β or γ.Thus, as against the statement in the description of applicationWO008201043 that the unit with meridian slots in female detail willoperate without slippage, we assert that individual balls in this designwill slip. If the interrupted groove is made in the wobble plate 43, andthe closed groove is in the case 42, the appropriate angular conditionφ=90°−β−γ<10° expands opportunities for a choice of angles β and Γ,however seasonings about slippage of balls in points E and F are kept inforce also for this variant.

In transmitting unit at FIG. 30 file of balls 46 cooperatessimultaneously with three periodic grooves. The groove 45 in the wobbleplate 43 is interrupted and is made in the form of slots spaced apartalong of circle. The case is composed of two individual independentlyrotating parts 56 and 57 having identical diameters and snap-together bytheir end faces. In internal side surfaces of these cases in a circle oftheir end face contact the periodic grooves 58 and 59 having differentperiods are made. On the diagram of FIG. 31 average lines of grooves 58and 59 are designated by numerals 60 and 61. By numeral 52 is designatedan average line of a periodic groove 45 in the wobble plate 43. In thisembodiment of transmitting unit, the groove 45 is made interrupted. Itis obvious that not all balls 46 will cooperate with cases 56 and 57simultaneously. The balls located on the left and on the right of zone Iat FIG. 31 will interact with the case 56, and balls located in zone Iwill interact with the case 57. The gear ratio of the unit depends on aproportion of period numbers of all three grooves that expands a rangeof the gear ratio.

Let us consider now speed converters including the above describedtransmitting units. The speed converter at FIG. 32 is realized withtransmitting unit having the closed periodic grooves in the case 42 andin the wobble plate 43. The speed converter comprises three coaxialhollow shafts 62, 63 and 64. The shaft 62 is connected to the wobbleplate 43 by means of mechanism transferring the rotation of a shaft 62into wobbling movement of the plate 43. Said mechanism representsannular ledge 65 made on an external side surface of the shaft 62 andconjugated to annular groove 66 in the wobble plate 43. Between oppositewalls of the groove 66 two balls 67 are located diametrically oppositeeach other at the different sides of the annular ledge 65. Duringrotation of a shaft 62, each ball 67 runs over its raceway formed by aannular ledge 65 and opposite walls of a groove 66 thereby causingwobbling movement of a plate 43. The mechanism also operates in theopposite direction, i.e. wobbling movement of a plate 43 will cause therotation of a shaft 62. It is necessary to note, that unlike a swashplate in the disclosure of application WO8201043 which transfers effortonly in one half-cycle of wobbling, the above mechanism operates in bothhalf-cycles. The shaft 63 is connected to the wobble plate 43 bymechanism transferring its rotation irrespective of wobbling movement.In this embodiment, transferring mechanism represents a bevel gear 68.The third shaft of the speed converter is the case of transmitting unitwith a groove 44 on the side surface. Hollow shaft 64 is set on a shaft62 by means of the bearing 69. A shaft 63 is aligned between shaft 62and 64 by means of bearings 70 and 71. By numeral 72 there is designateda thin-walled separator which is necessary in individual transmittingunits to hold balls at identical angular distance from each other inthat locus where tangents to grooves in the place of their intersectingare parallel each other (in points B and D at FIGS. 23, 25 and 27). Theseparator follows the form of conjugated surfaces, i.e. also is aspherical belt. Sockets of the separator 72 are formed as throughapertures. Here it is necessary to note, that a separator is a necessaryelement only for individual variants of transmitting unit. Inparticular, a separator is not necessary for transmitting units with thehigh gear ratio and with high accuracy of manufacturing of groove. Theconverter represents the differential mechanism with two inputs andsingle output. In the reducer mode the input of converter is the shaft62, one revolution of which causes one full wobbling of plate 43. If oneof shafts 63 or 64 is fixed, i.e. connected to the frame of drivemechanism, then other shaft will be output. If one of shafts 63 or 64rotates with the speed differing of that of input shaft, then outputspeed will depend on a ratio of speeds at inputs. In a mode of themultiplier any of shafts 63 or 64 should be input.

Let us consider functioning of the converter in a mode of a reducer. Forconcrete definition assume the shaft 64 is connected to frame. Inputshaft is the shaft 62, when it rotating, balls 67 are involved inrevolving around orbit and cause precession of plate 43. Since the case42 is immovable, ball 46 interacting with grooves 44 and 45 causerotation of the plate 43 with the transfer ratio determined by anexpression (3). Rotation of a plate 43 is transferred to an output shaft63 by means of a bevel gear 68. Losses to friction, noise anddeterioration are minimal in this transmitting unit as it operates inconditions of pure rolling of balls, it is necessary to note, that theconverter with friction-planetary unit will operate as above described,but its transfer ratio will different. The speed converter with thetransmitting units according to FIGS. 18 or 30 is supplied with theadditional shafts directly connected to parts of a case. Thus the numberof possible modes of the converter operation is increased.

In the embodiment of the converter shown at FIG. 33 the shaft 63 is anon-rotating part and it is formed by two flanges 73 and 74 connectedwith each other and with a frame. The wobble plate 43 is connected toflanges 73 and 74 by means of two face tooth gearings 75 and 76. Use oftwo tooth gearings as the mechanism transmitting rotation raises anumber of tooth being in driving engagement and increases thetransmitted moment. Shafts 62 and 64 are mounted in flanges 73 and 74 bymeans of bearings 77, 78, 79, 80. The mechanism transferring wobbling ofa plate 43 to rotation of a shaft 62 and on the contrary is the coaxialfriction-planetary transmitting unit similar to that represented on FIG.10. There two ring grooves 24 and 29 in a shaft 62 engage with a groove25 in a wobble plate 43 by means of two balls 26 and 30. Instead of thisunit any of above coaxial friction-planetary units may be used.

Variants of converters at FIGS. 34 and 35 differ from each other in bothdesign of mechanism transferring rotation of a shaft 62 into wobbling ofa plate 43 and design of mechanism transferring rotation of a wobbleplate 43 to a shaft 63 irrespective of wobbling. In the converter atFIG. 34 the first of the transferring mechanisms is embodied on thebasis of a skew crank 81 set on a shaft 62. The wobble plate 43 ismounted by means of the bearing 82 on the skew crank 81. For transfer ofeffort from a skew crank by both half-cycles of the plate 43 wobbling,the bearing 82 is embodied as the annular four-point bearing. Themechanism transferring the rotation represents gimbals joint 83 by meansof which the wobble plate 43 is connected with hollow shaft 63. Bearings69 and 84 align shafts 62, 63 and 64 from each other. The mechanismtransferring wobbling movement of a plate 43 to rotation of a shaft 62at FIG. 35 is similar to the mechanism at FIG. 32, only that the annularledge 85 is made on the plate 43, and annular groove 86 is made in theside surface of a shaft 62. As the mechanism transferring the rotationat FIG. 35, the system of flexible rods or hinges 87 which allowswobbling of plate 43 irrespective of rotation of a shaft 63 is used.

In two-stage coaxial speed converters at FIGS. 36 and 37, transmittingunits of both stages are realized by means of single wobble plate 43.One of the transmitting units is formed by periodic grooves 45 and 44 onside surfaces of the wobble plate 43 and the hollow shaft 64 being acase of transmitting unit, and also by a file of balls 46. The mechanismtransferring rotation of a shaft 62 into wobbling of the plate 43represents a skew crank 81 on which through the annular four-pointbearing 88 the wobble plate 43 is mounted by shoulder 89. For reliableset of the wobble plate the similar shaft 90 with skew crank 91 isintroduced at the opposite end face of the converter. On the shaft 90through the same bearing 92 the opposite end face of a plate 43 is setby shoulder 93. Transmitting unit of the second stage is formed byperiodic grooves 94, 95 and by a file of balls 96. The groove 95 is madein the side surface of the plate 43 opposite to a surface with a groove45 of the first transmitting unit. The groove 94 is made in the sidesurface of the hollow shaft 97 faced to a wobble plate 43. Separators oftransmitting units of both stages are designated by numerals 72 and 98.Shafts 62, 64, 90 and 97 are combined into united junction by means ofbearings 99, 100, 101 and 102 located on end faces of the converter.Shafts 62 and 90 rotate as single shaft and cause the wobbling movementof a plate 43.

The variant of the speed converter represented at FIG. 37, differs fromthe variant at FIG. 36 only by the mechanism transferring the wobblingmovement of a plate 43 into rotation of the shaft 62 and on thecontrary. The mechanism represents face cams 103 and 104 at the faced toeach other end faces of shafts 62 and 90; said face cams interact withend faces of a wobble plate 43 through thrust face bearings 105 and 106.Application of two oppositely laying face cams enables powertransferring during both half-cycles of the plate 43 wobbling. By thatthe described converter favorably differs from converters in thedisclosure of application WO8201043, where all mechanisms of a platewobbling operate only during one half-cycle. The two-stage converterworks as follows. When one of shafts, for example, shaft 62 (togetherwith the shaft 90) is rotated by external drive, plate 43 begins towobble. The rotation of the input shaft is not transferred to a wobbleplate, since it is untied with the shaft by bearings 88, 92 or 105, 106.This wobble movement of a plate 43 by means of interacting of grooves 44and 45 with balls 46 causes rotation of a wobble plate 43 relative tothe shaft 64 by angle determined by the period proportion of the grooves44 and 45. If the condition of self-blocking of balls 46 in grooves 44and 45 is satisfied, then balls 46 run in grooves without slippage.Transmitting unit of the second stage is formed by periodic grooves 94and 95 and by balls 96, and it operates similarly, only the input partof it is a wobble plate 43, which simultaneously wobbles and rotates.Thus, for the first stage of the converter, the function of themechanism transferring rotation of a wobble plate 43 carries out thetransmitting unit of the second stage. The output shaft of the converterin this variant is the shaft 97, the rotation speed of which relative toshaft 62 is determined by the rotation speed of the shaft 64 and by theproportion of groove period numbers of the first and the second stages.It is necessary to note, that input or output shafts can be any ofshafts 62 (or 90), 64 and 97. Thus, depending on a speed ratio of twoinput shafts, the converter works as multiplier or reducer (with one ofshafts motionless), or as the differential speed converter.

Coaxial two-stage converters at FIGS. 38 and 39 are formed by twotransmitting units, male and female. Transmitting unit of the firststage comprises a wobble plate 43 with a periodic groove 45, hollowshaft-case 64 with a groove 44, and a file of balls 46. The mechanismtransferring wobbling movement of the plate 43 into rotation of theshaft 62 represents skew crank 81 with the annular four-point bearing 88on which the plate 43 is set. The opposite side surface of the shaft 62is provided with skew crank 107, inside of which by means of the samebearing 108 the wobble plate 109 of the second stage is set. At an innerside surface of the plate 109 the transmitting unit of the second stageis realized. It comprises periodic grooves 110 and 111 in the plate 109and in the hollow the shaft 112, and a file of balls 113. Skew cranks 81and 107 can have an opposite inclination, as it is shown at FIG. 38, orthey can have identical inclination. Accordingly, plates 43 and 109wobble with opposed phases or synchronously. The first variant is morepreferable, as there the wobble plates are weight balanced relative toan axis of the converter. The plates 43 and 109 are connected with eachother by means of mechanism transferring rotation irrespective of theirwobbling movement. At FIGS. 38 and 39 this mechanism represents aflexible ring 114. At FIG. 38 the shafts 62, 64 and 112 at their endfaces are connected by bearings 101 and 102.

The converter at FIG. 39 differs by mechanisms transferring wobblingmovement of plates 43 and 109 to rotation of the shaft 62. Thesemechanisms are formed as friction-planetary transmitting units withgrooves 115 at opposite side surfaces of the shaft 62, two parallel toequator grooves 116 and 117 made in both wobble plates, and two pairsdiametrically opposite balls 118 and 119 in these grooves. By numerals120 and 121 the bearings are designated by means of which shafts 62, 64and 112 are fixed relative to each other.

The operating of these two-stage converters is similar to previous that.

In the two-stage converter with a stages arranged in series at FIG. 40,the transmitting unit of the first stage is formed by a wobble plate 43and by shaft-case 64 with balls 46 in grooves 44, 45. The unit of thesecond stage is formed by a wobble plate 122 set at second skew crank123 on the shaft 62 by means of annular four-point bearing 124. Theplates 43 and 122 are parallel each other. A hollow shaft 125 embraces aplate 122 and is being a case of the second stage. At the faced surfacesof a wobble plate 122 and a case 125 the periodic grooves 126 and 127are made. A file of balls 128 is located in said grooves. The precessionaxes OO₁ and CC₁ of the wobble plates 43 and 122 accordingly areparallel each other and are off-center displaced from each other.Therefore mechanism transferring rotation of one plate into another inthe given design represents mechanism transferring rotation betweenparallel shafts in the form of a ball parallel crank. It representssockets 129 and 130 in the end face surfaces of wobble plates 43 and122, which sockets are engaging with each other by means of balls 131.The axes of sockets are regular spaced along of a circle of each plate,and the diameters of sockets are more than a diameter of ball 131 byvalue of displacement axes of wobble plates 43 and 122 from each otherwhen they synchronously precess relative to points A and B. When platesprecess, balls 131 running in sockets 129 and 130 allow to plates 43 and122 to be displaced, but do not allow them to rotate relative eachother. Thus, the rotation of one of plates causes the rotation ofanother, thus the balls 131 allow surfaces of plates to be displacedfrom each other, while keeping an opportunity of their precessionrelative to own centre. Hollow shafts 64 and 125 can rotateindependently from each other due to presence of bearings 132 betweenthem. All three shafts 62, 64 and 125 of converter are assembled inunited node by means of bearings 133 and 134. A separator of the secondstage transmitting unit is designated by numeral 135.

The following embodiment of the two-stage converter represented at FIG.41 differs by the mechanism transferring rotation of the shaft 62 intowobbling movement of plates 43 and 122. This mechanism contains twodiametrically opposite balls 136 and 137 which are located between agroove 138 in external side surface of the shaft 62 and annular ledges139 and 140 of plates 43 and 122. For simplification of assembly, thecase 125 is split along of a line dividing the periodic groove 126 intotwo symmetric parts. The shafts 62, 64 and 125 are incorporated by meansof bearings 132, 133, 134.

Variant of the two-stage converter shown at FIG. 42 has two wobbleplates 43 and 122 wobbling in the opposite phases. For this purpose skewcranks 141 and 142 with an opposite inclinations are provided on theshaft 62. The coupling of cases is carried out by bevel gear wheels 143and 144. All other designations at FIG. 42 correspond to designations atFIG. 40 and 41.

Two-stage converter at FIG. 43 differs by original designs both themechanism transferring rotation of the shaft 62 into wobbling movementof plates 43 and 122, and the mechanism transferring rotation betweenplates 43 and 122 irrespective of their precession. The shaft 62 isformed as a case with skew cranks 81 and 123. at external side surfaceof said case. Moreover, shaft 62 in the middle part has external annularledge 145 exceeding the bounds of shafts 64 and 125. External tooth rowof annular ledge 145 is formed as a bevel gear wheel 146 engaging awheel 147 at the shaft 148. Such mechanism transfers rotation betweeninclined shafts 62 and 148. In this converter the power take-off can bemade simultaneously from cases 64 and 125, therefore the converter isvery effective as a reducer of the automobile back axle. Hollow shaft149 coupled to plates 43 and 122 by means of two gimbals joints 150 and151 passes through internal cavities of the shaft of 62 and wobbleplates 43 and 122. Gimbals joints 150 and 151 allow free wobbling ofplates 43 and 122 while transferring rotation from each other. Numerals133 and 134, as well as in the previous Figures, designate bearingsconnecting elements of the converter with each other.

Two-stage converter with arrangement of stages in series operates in thefollowing way. Assume that the shaft—case 64 of first stage ismotionlessly fixed. The rotating of the shaft 62 with angular velocityω₁ causes the precession of wobble plate 43 with the same velocity. Whenprecessing, the wobble plate 43 forces balls 46 and causes their runningwithout slippage in immovable groove 44 of the case 64 with velocity ω₂depending on period number of this groove. The running of balls 46, inturn, causes the rotation of a plate 43 relative to a file of balls,which rotation depends on period number of the groove 45 in the wobbleplate 43. The wobble plate 43 rotates relative to immovable case 64 withangular velocity ω₃ being the function of period numbers of groove 44 inthe case 64 and groove 45 in the plate 43. The rotation of the wobbleplate 43 is transferred to the wobble plate 122 by means of eitherparallel crank balls 131 or teeth of wheels 143 and 144 or shaft 149with gimbals joints 150 and 151. The wobble plate 122 simultaneously isin rotation and in precession with angular speed ω₁. The balls 128 ofthe second transmitting unit interacting with both a groove 126 in theplate 122 and a groove 127 in the case 125 cause rotation of the lastrelative to plate 122 by an angle determined by the ratio of the periodnumbers of grooves 126 and 127. The total rotation of the drivenshaft—case 125 depend on angular velocities ω₁, ω₂, ω₃ and, at the end,it is determined by numbers of the periods of all four grooves in wobbleplates and in cases of transmitting units both stages. If the shaft 64rotates, i.e. it is the second input shaft; output velocity depends,among other things, also on the ratio of input velocities of shafts 62and 64. The precession center of a file of balls 46 is the point A, andthe precession centre of a file of balls 128 is the point B. Thesecenters A and B coincide with the symmetry centers of the appropriateplates. That is, the precession of each file of balls is occurs relativeto a point lying in a plane of this file, that considerably simplifiesthe requirements to a groove contour.

Let us address now to FIG. 44 at which transmitting unit is representedin which two cases 152 and 153 are able to precess and so they arewobble pates. Just as in transmitting unit at FIG. 20, in the faced sidesurfaces of this cases being in the form of a spherical zones, theperiodic grooves 154 and 155 are made, at the intersection of thisgrooves a file of balls 156 is located. In such transmitting unit with acommon angle of an inclination between plates equal to γ, the tiltingangle of each plate to an axis OO₁ is γ/2. That is, the precession angleof each plate is reduced twice, that creates more favorable conditionsfor operate of the mechanism exciting the precession of plates, and alsofor mechanism transferring the rotation.

FIGS. 45 and 46 show a schematic drawing of speed converters, in whichplates 152 and 153 both wobble by the same angle, but in oppositedirections, i.e. precess in opposite phases. The precession is supportedby the mechanism in form of two hollow shafts 157 and 158 connected witheach other by means of flange 159. The shaft 157 is located inside oftransmitting unit, and shaft 158 is located outside of transmittingunit. Closed annular groove 159 and annular ledge 160 are made in theside faced to each other surfaces of the shaft 157 and the plate 152.Similar groove 161 and similar ledge 162 are made in the faced to eachother surfaces of other pair composed of shaft 158 and a wobble plate153. One ball 163 is entered between a wall of a groove 159 and annularledge 160 at the one hand of plate 152. Other ball 163 is enteredbetween the opposite wall of a groove 159 and opposite side of the ledge160 at the diametrically opposite hand of a plate. Just as, between agroove 161 and a ledge 162 two balls 164 are entered. The balls 163 and164 are located relative each other so, that provide an oppositeinclinations of plates 152 and 153. The plates 152 and 153 are connectedwith hollow shafts 165 and 166 by means of mechanisms transferringrotation between misalignment shafts. At FIG. 45 such mechanism isformed as system of levers or flexible rods 167 and 168; and at FIGS. 46and 47 similar mechanisms are formed as bevel gears 169 and 170.

The mechanism transferring the wobbling of plates 152 and 153 to rotarymovement of the shafts 157 and 158 connected with each other shown atFIG. 46 represents two skew cranks 171 and 172 with an oppositeinclinations set at the side surfaces of shafts 157 and 158 faced towobble plates. Wobble plates 152 and 153 are set at the crank shafts 171and 172 by means of annular four-point bearings 173 and 174.

Operation of speed converters at FIGS. 45 and 46 practically does notdiffer from operation of the converters represented at FIGS. 33 or 34.One of shafts, 165 or 166 is output part, and another is fixedmotionlessly. The power take-off is always made through mechanismtransferring rotation between misaligned shafts; and this mechanism isdesigned for a smaller tilting angle of shafts, than that for theconverter with single wobble plate. Moreover, the precession angle ofeach wobble plates is twice reduced, with other things being equal, i.e.the mechanism transferring wobbling movement of a plate into rotarymovement of the shaft and on the contrary operates by smaller angles.

The speed converter shown at FIG. 47 has two independently rotatinghollow shafts 175 and 176 provided with skew cranks located inside andoutside of transmitting unit. Wobble plates 152 and 153 are set at skewcranks by means of bearings 173 and 174. Crank shafts 175 and 176 formtwo inputs of the converter and cases 165 and 166 can serve as outputs.If the input shafts rotate with identical velocities and in the samedirection and skew cranks have an identical inclination, then plates 152and 153 wobble without rotation in one direction as a single whole. Theywill be immovable relative to each other, so the output speeds of theconverter will be equal to zero. If the direction one of input shafts ischanged to opposite, the converter transfers the torque with the gearratio determined by ratio of the groove period numbers in each wobbleplate. Thus, the speed converter gets an addition function of a coupler.

Thus, in the transmitting units with wobble plate described in theapplication there is no sliding friction between engaging parts, thatraises efficiency, reduces noise and deterioration of both grooves androlling bodies. Various designs of the speed converters with suchtransmitting units are constructed by a principle of the bearing, i.e.consist of several coaxial cases, each of cases can serve input oroutput shaft or frame, thereby changing mode of operation and functionsof the converter. Each of the described above units can be appliedseparately or together, forming designs for various applications,without departing from the spirit and scope of the invention.

While the above description contains many specifics, these should not beconstrued as limitations on the scope of the invention, but rather asexemplifications of one or another preferred embodiment thereof. Manyother variations are possible, which would be obvious to one skilled inthe art. Accordingly, the scope of the invention should be determined bythe scope of the appended claims and their equivalents, and not just bythe embodiments.

1-47. (canceled)
 48. A motion transmitting unit with a wobble plate,said motion transmitting unit comprising two members in form of solidsof revolution, one of said member is arranged to make two independentmovements: wobbling relative to another member and rotation around of anown axis inclined to an axis of other solid of revolution, and saidmember is a wobble plate, on the members surfaces faced to each otherendless annular grooves are made interacting with each other by means ofrolling bodies being in continuous contact with said grooves, and thetilt angle of a wobble plate is chosen so that said grooves in a placeof contact with rolling bodies are inclined with respect to each otherby angle less or equal to the angle of self-blocking of rolling bodies.49. The motion transmitting unit according to claim 1 differing in thatsaid grooves are inclined with respect to each other by angle in therange of 0,1 up to 10 degrees.
 50. The motion transmitting unitaccording to claim 1 differing in that the solids of revolution areformed as disks having on the faced to each other flat surfaces theannular closed grooves contacting with each other by means of singlerolling body.
 51. The motion transmitting unit according to claim 3differing in that the rolling body is ball, and the side walls of agrooves are resilient flexing to each other.
 52. The motion transmittingunit according to claim 1 differing in that the solids of revolution arcmade in the form of a case and a wobble plate where one embraces theother, both having side surfaces faced to each other in the form of aspherical zones with the centre of sphere lying at the precession centreof a wobble plate, the rolling bodies are balls, and both grooves in thewobble plate and in the case are made in spherical zones of this membersas systems of closed annular grooves parallel with respect to each otherand laying in planes perpendicular to axis of rotation of theappropriate member, and the balls are located in points of intersectionsof the wobble plate grooves with the case grooves.
 53. The motiontransmitting unit according to claim 5 differing in that in the systemof grooves at least one groove in the case is made in separateindependently rotating part of the case.
 54. A motion transmitting unitwith a wobble plate, said motion transmitting unit comprising two solidsof revolution one of which embracing the other, one of which is a wobbleplate, and another is a case, both having side conjugated surfaces inthe form of spherical zones with the centre of sphere lying in theprecession centre of the wobble plate, in equatorial areas of theirspherical zones periodical in the azimuth direction grooves are made, atleast one of which is endless wavy bent in the axial direction; saidgrooves engage each other by means of a file of balls located in placesof grooves intersections, differing in that said grooves in a places ofcontact with balls are inclined with respect to each other by angle lessor equal to the angle of self-blocking of balls.
 55. The motiontransmitting unit according to claim 7 differing in that the angle α ofinclination of the periodic groove front with respect to equatorial lineof the wobble plate and appropriate angle β at the case are in thefollowing ratios to the tilt angle γ of the wobble plate: α−β−γ≦10° ifα≧β (1); β−α+γ≦10° if α<β.
 56. The differential speed convertercomprising at least three shafts and the transmitting unit accordinglyto any of claims 1-8, differing in that the wobble plate is connected toone of shaft by means of mechanism for independent transferring of itsprecession motion into rotary and on the contrary, with other of shaftssaid wobble plate is connected by the mechanism transferring itsrotation relative to inclined axis independently of wobbling movement,the second solid of revolution is directly connected to the third shaft.57. The differential speed converter according to claim 9 differing inthat the transmitting unit is formed as claimed in any of claims 5-8,and all shafts are hollow coaxial thereby forming a coaxial designcomposed of cases just as bearing unit.
 58. The differential speedconverter according to claim 10 differing in that the transmitting unitis formed as claimed in claim 6 and is supplied with additional shafts,each of which is directly connected to one of the separate parts of thecase.
 59. The differential speed converter according to claim 10differing in that the mechanism transferring precession motion of aplate into rotation and on the contrary is formed as claimed in claim 5and is realized on the same wobble plate at its side opposite to thebasic transmitting unit, and the case of said mechanism is directlyconnected to the first shaft.
 60. The differential speed converteraccording to claim 10 differing in that the coaxial transmitting unit ofthe second stage is entered in addition, said second stage unit isformed as claimed in any of claims 5-8 and is realized on the samewobble plate of the first transmitting unit at wobble plate sideopposite to first transmitting unit, any of said transmitting unitscarries out the function of the mechanism transferring the rotation ofthe wobble plate to the shaft directly connected to the case of thesecond stage transmitting unit.
 61. The differential speed converteraccording to claim 10 differing in that transmitting unit of the secondstage is entered in addition being coaxial to First transmitting unitand made as claimed in any of claims 5-8, the second stage transmittingunit is located relative to the first unit so that the wobble plates ofboth units are faced to each other, the mechanism transferringprecession motion of each of plates into rotation is made in the form ofhollow shaft entered between said wobble plates of the first and thesecond stages and having at its internal and external side surfaceselements causing the precession of said plates, and the plates of bothstages are connected with each other during rotary movement so thattransmitting unit of the second stage simultaneously carries out thefunction of the mechanism transferring rotation of the wobble plate tothe shaft directly connected with the case of the second stagetransmitting unit.
 62. The differential speed converter according toclaim 14 differing in that the elements causing precession of the wobbleplates are formed at the side faced to each other surfaces of the hollowshaft and each of wobble plates in the form of annular groove andannular ledge conjugated with each other by means of two diametricallyopposite balls located between walls of the groove and ledge at theopposite sides of the last.
 63. The differential speed converteraccording to claim 10 differing in that the transmitting unit of thesecond stage is entered in series to the first stage transmitting unit,and said second stage transmitting unit is made as claimed in any ofclaims 5-8, the wobble plates of both stages are connected by themechanism transferring rotation between parallel shafts, and themechanism transferring precession motion provides the synchronousprecession of plates.
 64. The differential speed converter according toclaim 10 differing in that the transmitting unit of the second stage isentered in series to the first transmitting unit and formed as claimedin any of claims 7-9, the wobble plates of both stages are connected bythe mechanism transferring rotation between inclined shafts, and themechanism transferring precession motion into rotation and on thecontrary provides the precession of the plates in opposite phases. 65.The motion transmitting unit with a wobble plate according to claim 7,differing in that both cases are mounted to precess and are the wobbleplates.
 66. A differential speed converter comprising at least threeaxial hollow shafts forming a coaxial design composed of cases just asbearing unit and transmitting unit formed as claimed in claim 18, wherein the wobble plates are connected to two shafts by mechanismstransferring rotation between inclined shafts, and said wobble platesare connected to other shafts of the converter by mechanisms forindependent transferring of precession motion into rotation and on thecontrary.